Best time to fly Boston to Charlotte

Every month pooled across the years on record, so "July" means July generally rather than one particular July. Full BOS to CLT record →

Best month

April

90.6% on time · 339 flights

Worst month

September

71.8% on time · 318 flights

Month Flights On time Cancelled When late, by
January 291 80.6% 11% 109 min
February 275 83.6% 8.73% 75 min
March 327 84.7% 1.83% 67 min
April 339 90.6% 0% 52 min
May 355 86.2% 0% 84 min
June 352 88.2% 0.85% 91 min
July 359 73.2% 5.29% 91 min
August 353 87.1% 0.85% 97 min
September 318 71.8% 1.89% 79 min
October 370 76.8% 1.08% 75 min
November 347 84% 2.88% 92 min
December 331 83.3% 0.3% 60 min

What a seasonal pattern can and cannot tell you

Months differ for reasons that repeat — summer thunderstorms in the American interior, winter fog and de-icing in northern Europe, school holidays filling every seat and leaving no slack in the schedule. Those are real and they come back each year.

What the pattern cannot do is forecast a particular flight. A quiet month has late days and a bad month has punctual ones. Treat this as a way to choose between two dates you are indifferent about, not as a promise.